Rare Glimpses of Great White Sharks Scavenging Surprise Researchers

By Gemma Tarlach | April 10, 2013 12:10 pm

When a dead whale turns up in False Bay, on the South African coast, guess who’s coming to dinner?

The answer surprised even the researchers studying the feeding event. In a study published in the open-access journal PLOS One, researchers observing False Bay’s famous great white sharks (Carcharodon carcharias) observed that scavenging events changed the sharks’ behavior markedly—and attracted much larger sharks than typically seen in the area. The findings are important because little is known about how or how often sharks scavenge, though scientists hypothesize that scavenging is a crucial activity for the apex predator.

False Bay has become internationally known for its sharks thanks to the population’s density and high-profile media coverage of some of them leaping out of the water to catch seals. The famous airborne sharks of the area, according to the study, are typically 9-12 feet in length. On four separate scavenging occasions, however, researchers noted that whale carcasses attracted several sharks up to 18 feet in length. Many of the larger individuals had not been previously observed by the team, which has been conducting research in the area since 1997 and has identified and tagged scores of sharks during that time.

Observation of the scavenging events found the sharks methodically eating first the whale’s fluke and then the most blubber-rich areas of the carcass, sometimes regurgitating one bite to make room for a second, more calorically-rich morsel. This pattern is further evidence that white sharks are adept at assessing the caloric value of their food and are selective when feeding. During one scavenging event, for example, a 13-foot-long shark was observed moving into the carcass to reach and remove a near-term fetus from the dead whale’s uterus, which it then consumed.

Because C. carcharias lacks the protective nictating membrane some other sharks have, it typically rolls its eyes back in their sockets at the moment of attack to avoid being injured or even blinded by struggling prey, a behavior known as ocular rotation. Researchers at the whale carcass events, however, did not observe any ocular rotation among the sharks feeding.

Perhaps even more surprising, despite the number of sharks feeding at the same time—even bumping into each other, according to researchers—there were no displays of aggression or “feeding frenzy” behaviors. At various times during one scavenging event, for example, three or more large sharks (approximately 16 feet long) fed “belly-up next to each other…with their pectoral fins overlapping,” without incident, according to the study.

The team documented the four separate scavenging events as part of its long-term study of the False Bay population. When a whale carcass was noted in the area, researchers anchored their boat alongside the carcass to better observe the sharks’ behavior and estimate the size of the predators feeding.

The study’s findings are particularly important because, despite its ubiquitous presence in pop culture, many aspects of C. carcharias’ behavior remain a mystery. Being able to observe the apex predator’s scavenging of whale carcasses is a particularly rare event: According to the study, since 1896 only 19 such events have been recorded in scientific literature, and only two of those studies focused specifically on the sharks’ behavior.

Image courtesy Fallows, et al., PLOS ONE

CATEGORIZED UNDER: Living World, top posts
MORE ABOUT: ocean, sharks
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  • One Shot

    I find it curious that no other shark species were mentioned. If there were no others it should be mentioned. Tigers feed on humpback carcasses around Hawaii. It would be an interesting comparison of the species’ behavior.

    • El Gavilan Pollero

      VENDO TRES TIBURONES AMAESTRADOS QUE SABEN CANTAR ,BAILAR Y SUMAR HASTA EL DIEZ. ESTO ES TREMENDA GANGA. Y LOS VENDO BIEN BARATOS.

      • One Shot

        Pardona me no hablo espanol

        • El Gavilan Pollero

          I am sorry, I do not whrite in inglish and i make to many mistakes as you can see. But we can be good friemds no matter the language bye

  • http://www.facebook.com/people/Jeremiah-Blondin/100000172218405 Jeremiah Blondin

    It’s interesting that they don’t frenzy when scavenging on whales. I wonder if it a) feeding frenzies are triggered by the presence of multiple sharks and fresh blood in order to reduce hunting competition so an already dead animal doesn’t trigger the response or b) the whale carcass is so large that the sharks never “feel the need” to compete for it. It would be interesting to see whether or not they frenzy when multiple sharks encounter a single smaller carcass.

    • El Gavilan Pollero

      YO TENGO UN TIBURON EN EL BAÑO DE MI CUARTO QUE LO ALMUERZA SON PURAÑAS DEL AMAZONA Y TENGO QUE PESCARLAS CON MOSCAS.

  • Just me

    The researchers job is a very dangerous one. Not everyone would have the guts to get up close and personal to scavenging great white sharks. People would be on their menu too. False Bay would not be a good place to go snorkeling.

  • Ahmed

    I think it’s not the first time than a fish scavenge on white whale carcass, I believe there was many frenzy operations upon all the ages, that have consumed a lot of life styles in the ocean, this is only one of them and the one we have noticed.

  • http://www.facebook.com/Almac68 Alan McKenzie

    I visited the Natal Sharks Board. It was interesting to know that their work was transformed from protecting the beaches of Durban to the conservation of all sharks. White shark are stunning creatures and still very much misunderstood. As for eating people, sharks can not digest human flesh. A surfer paddling out on the water is mistaken for a weak turtle. Sharks will prefer not to chase its food, often go weeks without eating, patrolling coastlines where warm and cold sea currents are. Where river mouths silt up creating good breaks. So surfers and sharks share the same territory. I do fear that sharks are disappearing at an alarming rate, for the sake of fins for soup.

  • Whitese7en

    Damn nature you scary!

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